IDoom

iDoom is a Doom port for the  developed by Benjamin Eriksson, alias Hyarion and Mattias Pierre, alias Jobbe. It is built from the original Linux Doom source code that id Software released in 1997.

History
The idea to port Doom to the iPod started in September 2004 when a developer known as Edit0r started initial developments. This version was halted after two months of development due to a lack of programming knowledge. In November 2004 another developer called Aegray used Nano-X Doom, a port of Doom to to compile for the iPod. Shortly thereafter, a working but very unoptimized version for the by another developer known as wCars05.

iDoom materializes
It was around this time that Benjamin Eriksson downloaded the source code to Nano-X Doom (not to be confused with NxDoom) and started tinkering. A first version of this modified port got released, but Eriksson realized it would be simpler and more efficient to start from scratch using the original Linux Doom source code. Together with Mattias Pierre, alias Jobbe, they set out to provide a fast and nice looking port for every iPod running the system.

The first version under the iDoom umbrella was released as version 1.0 on October 4, 2005. Version 1.1 followed a month later on November 5, introducing support for the 1G and  models. A bugfix release known as 1.1a followed on November 10 to restore iPod Photo support.

2006 saw the release of iDoom 1.2, being released on January 15, 2006. It supported improved menu controls, optional wheel turning via a configuration file and fixing a bug regarding loading so that iDoom now could both load and save games. A final release followed on May 18, 2006 as version 1.3. This release introduced support for the, also known as 5G Video. The source code of this version also was released.

Features

 * Supported models:
 * iPod 1G, 2G, 3G, 4G, 5G
 * iPod Mini 1G, Mini 2G
 * iPod Nano 1G
 * iPod Photo
 * iPod Color Display (part of the iPod 4G line)
 * Scaled to the specific iPod's native resolution. These include:
 * iPod 1G, 2G, 3G, 4G: 160x128
 * iPod 5G: 320x240
 * iPod Mini 1G, 2G: 138x110
 * iPod Nano 1G: 176x132
 * iPod Photo, iPod Color Display: 220x176
 * Full color version with 256 colors, like the original Doom for the following models:
 * iPod 5G
 * iPod Nano 1G
 * iPod Photo
 * iPod Color Display
 * Dithered graphics for grayscale iPod models
 * 10-20 FPS (only 8 FPS for iPod 1G, 2G and 3G due to a hardware bug causing broken cache present on the PortalPlayer 5002 used by these models)
 * Ability to use different WAD files
 * Configurable controls via config file

Planned features
There were plans to improve the port even further as noted by the author's to-do list:
 * Wider WAD files support
 * Sound
 * Using the co-processor to speed things up
 * Generally increase the frame rate

Trivia

 * It is possible to run iDoom on the updated iPod 5G, known as 5.5G, albeit support is limited due to iPodLinux support being unstable for this version of the iPod.